improved test input to ensure error message is accurate for the corre…

…sponding msgid without msgstr

tests/messages/test_pofile.py

@@ -1016,6 +1016,8 @@ def test_issue_1087():
     assert pofile.read_po(buf).locale is None
 
 def test_issue_1134():
-    buf = StringIO(r'msgid "this is an invalid po file"')
+    buf = StringIO('''msgid "this is an invalid po file"
+msgstr "hello world"
+msgid "msgid without str"''')
     with pytest.raises(pofile.PoFileError):
         pofile.read_po(buf, abort_invalid=True)